This proposal focuses on the biogenic amines, prostaglandins, and catechol estrogens of the uterus and its blood vessels--their turnover, receptor binding and interrelationships as they modulate uterine blood flow. Uterine and vascular content of pertinent substances will be determined by high performance liquid chromatography coupled with appropriate detection techniques. Biochemical studies will be complemented by physiologic/pharmacologic studies and morphologic examinations to determine if biogenic amines, prostaglandins, and/or catechol estrogens are key substances in the regulation of uterine blood flow. Studies proposed for the immediate future will examine the functional significance of the binding and metabolism of estradiol by the uterine paracervical ganglion and will extend our investigations of a potential role for luteinizing hormone releasing hormone in uterine vascular effects of estrogen.